Audio system



FIG. 1 is a front, side perspective view of an audio system, showing our new design;

FIG. 2 is a back, top, opposite side perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is an opposite side view thereof; and,

FIG. 8 is a side view thereof.

The broken line portions of FIGS. 1-8 are included to show unclaimed subject matter only and form no part of the claimed design. 

CLAIM The ornamental design for an audio system, substantially as shown and described. 